Multiphase DC-DC converters use multiple phases to produce current to a load of the DC-DC converter. The output of the DC-DC converter is monitored to determine the level of the output voltage provided by the phases. Typically, each phase is instructed to provide the same amount of current. The phases are designed to be identical, but process variations can result in different resistances of the phases and consequently power losses.
These different levels of power losses can result in different temperatures at the phases. Since the operation DC-to-DC converter can be cycled thousands of times a day, there can be thousands of heating and cooling periods with resultant thermal stress that can damage the power supply.
One way to compensate for the differences in operating temperature of the phases is to use a temperature sensor. However, temperature sensors are expensive. Further, the temperature sensors are typically attached to the outside of the chip package and the intervening layers of packaging can interfere with the temperature sensing.